The EPA announced today that it is not changing current so-called “secondary” air quality standards for sulfur oxides and nitrogen oxides despite admitting that scientific evidence show that current standards are too weak. http://www.epa.gov/oaqps001/sulfurdioxide/pdfs/20120320factsheet.pdf
Secondary standards, as you probably know, are designed to protect against environmental damage from dirty air, as opposed to health impacts that are meant to be covered by “primary” air quality standards. EPA did note, accurately, that sulfur oxide and nitrogen oxides emissions have fallen during the past 30 plus years.
Was this yet another decision shaped by election-year considerations?
Last year, EPA’s science advisers concluded current standards aren’t good enough to protect acidification and other impacts on water bodies, and urged EPA to set a new multi-pollutant standard:
…the ISA, REA and draft PA [EPA technical documents] demonstrate that adverse impacts to aquatic ecosystems are also occurring due to deposition of NOx and SOx. Those impacts include acidification and undesirable levels of nutrient enrichment in some aquatic ecosystems. The levels of the current NOx and SOx secondary NAAQSs are not sufficient, nor the forms of those standards appropriate, to protect against adverse depositional effects; thus a revised NAAQS is warranted.” (Russell and Samet, December 9, 2010, EPA-CASAC-11-003)**
..overall CASAC finds that the Policy Assessment provides relevant scientific information needed for consideration in revising the secondary NAAQS for oxides of nitrogen and sulfur. We trust that our comments are useful to you and your agency in developing a proposal for a multipollutant NAAQS.
EPA’s own staff assessment called into question the adequacy of current standards:
… staff concludes that currently available scientific evidence
and assessments clearly call into question the adequacy of the current standards with regard to deposition-related effects on sensitive aquatic and terrestrial ecosystems, including acidification and nutrient enrichment. Further, staff recognizes that the elements of the current standards --indicator, averaging time, level and form – are not ecologically relevant, and are thus not appropriate for standards designed to provide such protection. Thus, staff concludes that consideration should be given to establishing a new ecologically relevant multi-pollutant,
multimedia standard to provide appropriate protection from deposition-related ecological effects of oxides of nitrogen and sulfur on sensitive ecosystems, with a focus on protecting against adverse effects associated with acidifying deposition in sensitive aquatic ecosystems.